Credit cards and also phone cards are used internationally on an ever-increasing scale. These are used instead of "hard money" and even instead of checks or traveller checks.
There exits a widespread use of credit cards for orders by telephone, where the owner of the card indicates his name and credit number. Furthermore, very frequently one of the copies of a voucher is lost or thrown away. Anyone who finds such a copy can use the credit card number for ordering by phone, and such misuse causes enormous losses to credit-card companies. The possibility to use such information for orders by phone is apt to cause serious losses due to the fact that the card owner and the company will generally become aware of the misuse only after a prolonged time, when the next list of expenses is submitted to the card holder.
Nowadays, a number of approaches is being used trying to overcome this problem. One of these is the recording on the card of only part of the required number, the card owner being required to remember a further number, generally of three or four digits, which is required for the use of the card. Such numbers are frequently forgotten or lost. Furthermore, this method is in use mainly for drawing money from a bancomat. Another technique is that the customer is required to apply his signature which has to match that on the card.
This is effective only with direct purchases and prevents to a certain extent misuses if a card is lost.
Another approach is the use, by credit card companies, of monitoring very frequent use of cards. This fails to distinguish between a business man and a thief making such frequent uses.